/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use
 * this file except in compliance with the License. You may obtain a copy of the License at the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>Unless required by applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apereo.portal.rendering;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apereo.portal.utils.cache.CacheKey;

/**
 * Base interface for rendering pipeline components. A component can return an event reader and a
 * corresponding cache key or just the cache key.
 *
 * <p>Implementations must be thread safe.
 *
 * @param <R> The event reader implementation
 */
public interface PipelineComponent<R, E> {

    /** Get the cache key for the request */
    CacheKey getCacheKey(HttpServletRequest request, HttpServletResponse response);

    /** Get the event reader and corresponding cache key for the request */
    PipelineEventReader<R, E> getEventReader(
            HttpServletRequest request, HttpServletResponse response);
}
